This invention concerns a building product, and particularly a building product in the form of an internal lining board.
There is a continuing movement to improve the energy efficiency of buildings, to inter alia reduce the carbon dioxide emissions associated with the built environment. Accordingly a number of steps have been made to produce more energy efficient buildings, including a number of retro fitting interventions. These though have often had negative unintended consequences relating inter alia to the poor management of moisture within the building, caused for instance by increasing the thermal resistivity and air tightness of buildings. This can lead to degradation of the building, unhealthy living environments and occupant health issues. The increasing of air tightness and thermal resistivity of buildings can lead to increased condensation, and hence cause mould growth.
The most commonly used internal lining product is plasterboard. The material of this product however has a very poor hygroscopic ability, i.e. the ability to absorb and desorb water vapours, and is not thermally insulating. Furthermore gypsum used to make plasterboard is a finite resource. Moreover plasterboard once finished with, does not produce a useful product for reuse or for instance composting.
Hemp (Cannabis Sativa) also known as industrial hemp and narcotic hemp, is a strain of Cannabis Sativa with a low level of tetrahydrocannaboids. It has been grown and used historically for many years, and historically was a much more significant crop than it is these days. Hemp fibres have had many uses, such as in rope or cloth. The shiv which is the woody core part of the plant stem, has however had far less uses. Hemp shiv generally consists of 19-21% lignin, 27-31% hemicellulose and 36-41% cellulose.